[PATCH 5.17 0533/1126] Netvsc: Call hv_unmap_memory() in the netvsc_device_remove()

Greg Kroah-Hartman
2022-04-05T09:50:55Z

From: Tianyu Lan <Tianyu.Lan@microsoft.com>

[ Upstream commit b539324f6fe798bdb186e4e91eafb37dd851db2a ]

netvsc_device_remove() calls vunmap() inside which should not be
called in the interrupt context. Current code calls hv_unmap_memory()
in the free_netvsc_device() which is rcu callback and maybe called
in the interrupt context. This will trigger BUG_ON(in_interrupt())
in the vunmap(). Fix it via moving hv_unmap_memory() to netvsc_device_
remove().

Fixes: 846da38de0e8 ("net: netvsc: Add Isolation VM support for netvsc driver")
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/hyperv/netvsc.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index afa81a9480cc..e675d1016c3c 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -154,19 +154,15 @@ static void free_netvsc_device(struct rcu_head *head)

kfree(nvdev->extension);

- if (nvdev->recv_original_buf) {
- hv_unmap_memory(nvdev->recv_buf);
+ if (nvdev->recv_original_buf)
vfree(nvdev->recv_original_buf);
- } else {
+ else
vfree(nvdev->recv_buf);
- }

- if (nvdev->send_original_buf) {
- hv_unmap_memory(nvdev->send_buf);
+ if (nvdev->send_original_buf)
vfree(nvdev->send_original_buf);
- } else {
+ else
vfree(nvdev->send_buf);
- }

bitmap_free(nvdev->send_section_map);

@@ -765,6 +761,12 @@ void netvsc_device_remove(struct hv_device *device)
netvsc_teardown_send_gpadl(device, net_device, ndev);
}

+ if (net_device->recv_original_buf)
+ hv_unmap_memory(net_device->recv_buf);
+
+ if (net_device->send_original_buf)
+ hv_unmap_memory(net_device->send_buf);
+
/* Release all resources */
free_netvsc_device_rcu(net_device);
}
@@ -1821,6 +1823,12 @@ struct netvsc_device *netvsc_device_add(struct hv_device *device,
netif_napi_del(&net_device->chan_table[0].napi);

cleanup2:
+ if (net_device->recv_original_buf)
+ hv_unmap_memory(net_device->recv_buf);
+
+ if (net_device->send_original_buf)
+ hv_unmap_memory(net_device->send_buf);
+
free_netvsc_device(&net_device->rcu);

return ERR_PTR(ret);
--
2.34.1